The title of the teleplay was originally Man of La Mancha, but sponsor DuPont Corp. objected and producer David Susskind changed it to the more specific I, Don Quixote, fearing that the TV audience would not know who Wasserman was referring to if the original title was used. When the teleplay was made into the famous stage musical, the writers decided to trust their audiences, and reverted the title back to Man of La Mancha.
I, Don Quixote has almost exactly the same plot and even much of the same dialogue as Man of La Mancha. Even the famous opening two lines of La Mancha's hit song The Impossible Dream were originally written as part of a spoken monologue by Wasserman, and not by lyricist Darion:
To dream the impossible dream,
To fight the unbeatable foe.
Wasserman noted that he had cut the impossible dream speech from the teleplay due to a need to fit the performance into the 90 minute slot, but that Lee J. Cobb had insisted it go back in.
I, Don Quixote starred Lee J. Cobb in the dual role of Miguel de Cervantes and Don Quixote, with Colleen Dewhurst (in her first major role) as Aldonza/Dulcinea, Eli Wallach as Cervantes' Manservant as well as Sancho Panza, and Hurd Hatfield as Sanson Carrasco as well as a character called The Duke.
Miguel de Cervantes and his manservant have been thrown into a dungeon by the Spanish Inquisition for an offense against the Church. In prison, a mock trial is staged, with its intention being that the prisoners rob Cervantes of all of his possessions, including a precious manuscript that he refuses to give up. It is, of course, the yet-to-be-published manuscript of Don Quixote de la Mancha, Cervantes's masterpiece. In defending himself, Cervantes begins to narrate his story of Don Quixote, with Cervantes as the Don, the role of Sancho enacted by Cervantes' own manservant, and the other characters in the story played by the other prisoners.
In the teleplay, however, there are fewer transitions from the prison to the Don Quixote scenes than there are in the musical. The teleplay also includes many adventures from the Cervantes novel which had to be left out of Man of La Mancha due to time constraints, such as the attack on the flock of sheep. The encounter with the windmills, instead of taking place in the early part of the story, as in both Cervantes' novel and the musical, here takes place towards the end.
There is some additional and unfamiliar dialogue heard in the 1972 film version of Man of La Mancha, starring Peter O'Toole and Sophia Loren. It is taken directly from the original TV play I, Don Quixote. It was restored to the film version of the musical after having been cut from the stage libretto.
The teleplay was highly acclaimed, but, oddly enough, did not win any Emmy nominations, although Dale Wasserman received a Writers Guild of America award for his work. After it was shown, Wasserman optioned it for Broadway, but the option was not picked up. Stage director Albert Marre finally read it and suggested that it should be turned into a musical, which, of course, is exactly what happened, and the rest is history.
I, Don Quixote has not been re-broadcast on television since 1959, and is reportedly only available on bootleg videos. Its script, however, was published in Dale Wasserman's memoir, The Impossible Musical.